/*
 * Licensed to Crate.io GmbH ("Crate") under one or more contributor
 * license agreements.  See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.  Crate licenses
 * this file to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.  You may
 * obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial agreement.
 */

package io.crate.expression.scalar;

import static io.crate.metadata.functions.TypeVariableConstraint.typeVariableOfAnyType;

import java.util.Locale;

import io.crate.data.Input;
import io.crate.metadata.FunctionType;
import io.crate.metadata.Functions;
import io.crate.metadata.NodeContext;
import io.crate.metadata.Scalar;
import io.crate.metadata.TransactionContext;
import io.crate.metadata.functions.BoundSignature;
import io.crate.metadata.functions.Signature;
import io.crate.types.DataTypes;
import io.crate.types.TypeSignature;

public class FormatFunction extends Scalar<String, Object> {

    public static final String NAME = "format";

    public static final Signature SIGNATURE = Signature.builder(NAME, FunctionType.SCALAR)
        .argumentTypes(DataTypes.STRING.getTypeSignature(), TypeSignature.E)
        .returnType(DataTypes.STRING.getTypeSignature())
        .features(Feature.DETERMINISTIC, Feature.NOTNULL)
        .typeVariableConstraints(typeVariableOfAnyType("E"))
        .setVariableArity(true)
        .build();


    public static void register(Functions.Builder module) {
        module.add(SIGNATURE, FormatFunction::new);
    }

    public FormatFunction(Signature signature, BoundSignature boundSignature) {
        super(signature, boundSignature);
    }

    @SafeVarargs
    @Override
    public final String evaluate(TransactionContext txnCtx, NodeContext nodeCtx, Input<Object>... args) {
        assert args.length > 1 : "number of args must be > 1";
        Object arg0Value = args[0].value();
        assert arg0Value != null : "1st argument must not be null";

        Object[] values = new Object[args.length - 1];
        for (int i = 0; i < args.length - 1; i++) {
            Object value = args[i + 1].value();
            values[i] = value;
        }

        return String.format(Locale.ENGLISH, (String) arg0Value, values);
    }
}
